1. Field
The present disclosure relates generally to communication systems, and more particularly, to using device-to-device (D2D) communications as part of an internet protocol (IP) multimedia subsystem (IMS) communications.
2. Background
Wireless communication systems are widely deployed to provide various telecommunication services to mobile users such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide common services that enable different wireless devices to communicate on a municipal, national, regional, and even global level. An example of a telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). LTE is designed to better support mobile broadband Internet access by improving spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards using OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology. LTE may support direct device-to-device (peer-to-peer) communication (e.g., LTE-Direct) between end user mobile devices such as mobile phones, smartphones, laptops, tablets etc. Such D2D communication would not need transport via a network and can thus reduce signaling, bandwidth and processing load on networks.
Services provided by wireless communication systems can include the ability to make and receive calls including voice calls and the ability to send and receive data including data transmitted using the Internet Protocol (IP). To make and receive voice calls with efficient usage of network resources (e.g., wireless spectrum and wireline signaling and transmission lines), networks and terminals may support Voice over IP (VoIP) for calls. Networks that support radio access according to 3GPP and 3GPP2 standards (which includes networks that employ GSM, WCDMA, cdma2000, EvDO, and LTE) may employ a solution in which support is provided using the IMS. IMS based communications use network based entities to aid and/or manage various functions and have been standardized by 3GPP for various radio access technologies including LTE.
Currently, when implemented in an access network, D2D communications allow for offloading of resources from network support to communications that may occur directly between devices. Because IMS based communications use network based entities to aid and/or manage various functions, the communications may not be able to fully function if handed off to D2D communications.
As the demand for D2D communications increases, there may exist a need for methods/apparatuses for using D2D communications to support at least a portion of IMS based services.